<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<script>
    function getItem(){
        var idArray = [];
        //得到所有选中的复选框
        var boxList = document.querySelectorAll("#roleDiv [name='roleArray']:checked ")
        for (var i=0;i<boxList.length;i++){
            idArray.push(boxList[i].value);
        }
        alert(idArray)
    }

    function setItem(){
        var arr = [1,3,4];
        for (var i=0;i<arr.length;i++){
            document.querySelector("#roleDiv [name='roleArray'][value='"+arr[i]+"']+").checked = true;
        }

    }
</script>
<body>
    拥有角色:<div id="roleDiv">
        <input type="checkbox" name="roleArray" value="1">普通用户
        <input type="checkbox" name="roleArray" value="2">业务员
        <input type="checkbox" name="roleArray" value="3">经理
        <input type="checkbox" name="roleArray" value="4">老板
    </div>
    <INPUT type="button" value="得到选中项" onclick="getItem()">
    <INPUT type="button" value="设置选中项" onclick="setItem()">
</body>
</html>